“This money came from all the puzzles you solved on that reward site. You solved so many so fast using my account that I’m a little afraid some counterintelligence people are going to be watching me, but this money definitely belongs to you. You can buy whatever you want with it and you don’t have to buy anything you don’t want. Think carefully about whether you want to save it or use it and make sure you don’t regret your decision.”

And then…

“Wahah! With this, I can eat ramen and tempura and pancakes and yakiniku and sushi and curry and Salisbury steak and gyudon and shabu-shabu and Chinese dumplings and Peking duck and sukiyaki and roast beef and fried chicken and oden!!”

“What did I just say!?”

Index slipped past the pointy-haired boy who was feeling faint and she ran from the student dorm with the calico cat.

However, she had not left in order to eat takoyaki with her dinner or anything like that.

“I’m gonna buy Touma a present. What should I get, Sphinx?”

Index seemed like the type who would simply get lost somewhere nearby, but she had a perfect memory. As long as she did not panic and then have trouble accessing her memories, visiting the shopping district near the station was simple.

But then…

“?”

She suddenly came to a stop.

Two girls wearing Tokiwadai Middle School’s winter uniform left a combination store that was not quite a bookshop, not quite a CD shop, not quite a rental shop, and not quite a game shop.

“That’s strange. Kuroko, didn’t this place used to have Monday releases a day early?”

“Selling things early is against the rules, so someone probably got after them about it.”

They were Misaka Mikoto and Shirai Kuroko.

The cat in Index’s arms began struggling at the appearance of this true high-class lady. It was likely sensing the “side effects” of her electric powers.

And Index had her own comment to make.

“Th-this money is important, so you can’t have it!”

“What!? Why are you treating me like a bandit the second you meet me!?”

Mikoto was about to grow horns from her head at the sudden false accusation, but the suspicion remained in Index’s eyes as she slowly and warily backed away.

“Touma said there’s a scary system that lets bad girls take your money if you make eye contact.”

“I don’t know what that idiot has to do with this, but this means I can go punch him, right?”

“And a thug who’s always acting all violent and zappy in the back alleys has to be a bad girl! So I need to be careful.”

“…Onee-sama.”

“Huh? Don’t you trust me at all? I don’t see why you would start glaring at me in Judgment mode.”

Suddenly, a large truck passed by the girls. It was Sunday morning, but it seemed the delivery business was still quite busy. Based on the logo on the side, it seemed to be carrying ingredients for restaurants.

Dust whirled into the air and wind was needed to pick that fine dust off the ground.

And that meant something else too.

Index watched as the two girls’ skirts were blown upwards.

Silence fell for a while.

Index did her best to keep her silence as the cloth rose, hovered, and was finally tugged back down by gravity.

The cat in her arms let out a mew.

Index then hesitantly held out the envelope that looked as pristine as if all the wrinkles had been ironed out.

“I’m sorry.”

“What!? Do I look that scary to you!? For one thing, I’m wearing shorts so it doesn’t really matter. And if you start shoving money toward me, it makes me look like the bad guy!”

“Honestly, Academy City is like a labyrinth today! It’s going to take a lot of work to complete this mission!”

“Ah…ah ha ha. Anyway, I think it’s good you settled that without causing any real trouble.”

A girl laughed bitterly while walking next to Index and poking at the pads on the cat’s front paws.

Her name was Kazakiri Hyouka. She had long black hair with a slight trace of brown and her most noticeable traits were the glasses that almost entirely defined people’s impression of her face and the plentiful breasts that symbolized her somewhat gentle aura. On top of that, she wore the navy blue blazer of Kirigaoka Girls School which was famous in a certain meaning of the word.

If one ignored the static that ran through her outline at any strong gust of wind or loud car horn, she looked like a perfectly normal high school girl.

Index’s friends such as Kazakiri Hyouka or Meigo Arisa tended not to be normal.

“So what are you going to give Kamijou-kun?”

“Anything that will make him happy!”

“I take it you didn’t research this at all.”

Index then froze in place.

Confused, Kazakiri followed the girl’s gaze and spotted a taiyaki stand made from a modified RV.

It even had a poster advertising a free taiyaki with any order of five or more.

“Something…to make Touma happy… Yes, this should make him happy. I know it will.”

“Y-you can’t, Index-chan! I have a feeling that choice will hurt you later!”

Kazakiri grabbed Index’s hand and pulled her away to prevent her from confusing her own desires for another’s happiness, but the two of them continued inching toward the stand. Everyone has likely forgotten, but Index’s base potential was quite high. It was just that the conditions for activating that potential were extremely limited: when the grimoire library’s safety activated, when food was involved, when Kamijou Touma required punishment, etc.

“Red bean paste…cheese…and they even have custard cream! But if I only buy one of each, we’ll fight over them, so I need to buy at least two of each!!”

“You can’t, you can’t, you can’t, Index-chan! You’ll end up eating them all yourself anyway!”

“Then I’ll buy three of each so you can have- whyah!?”

The two of them were stopped by a high-pitched sound.

The great noise that stabbed into their eardrums was that of breaking glass. They both looked over and saw a waitress girl had dropped a small drink bottle from her tray while walking between the tables in the open café placed around the taiyaki stand.

“Kyah! I-I’m sorry. I’ll go get a replacement right away.”

Meanwhile, drum-shaped cleaning robots arrived from all over and swallowed up the shards.

“And then I said loud and clear, ‘Do you really think you can live on supplements alone!?’ ”

The girl speaking proudly in front of Index was Tsuchimikado Maika.

She attended Ryouran Maid School and, simply put, was a maid-in-training. She wore the maid uniform even on her days off and she was sitting on top of a drum-shaped cleaning robot for some reason.

Index spoke while looking back and forth between the drum and the maid.

“Y-you are a greater summoner than I’d heard. You can use powers beyond those of man.”

“Hm? Don’t you see these cleaning robots all over the city?”

Maika cutely tilted her head, but she received no response.

As Index trembled in fear, the drum-shaped robot rocked back and forth as it battled a stubborn stain on the ground. It seemed to be a disastrous situation where some already-formidable gum on the road had pieces of a popped balloon caught in it.

Incidentally, Kazakiri Hyouka had vanished into thin air the instant Tsuchimikado Maika had called out to Index. For that friend, it was not a rare occurrence.

“Kamijou Touma was saying he wants a steam oven.”

“Steam?”

“They’re convenient and they completely change the repertoire of dishes you can make. He probably wanted to feed his roommate something good.”

“…”

Talk of cooking seemed to get her excited because Maika’s tone was tense.

At Index’s request, she guided the white nun to the cooking corner of an appliance store (and brought the cleaning robot with her).

“Are you sure this is what you want to buy? It’s not exactly a sexy gift.”

“It’s fine. If it makes Touma happy, that’s all that matters.”

The box was large and heavy, so she arranged to have it delivered. But despite living there, Index did not know the dorm’s exact name or address. That unwelcome surprise forced her to get Maika’s help again.

After parting ways with Tsuchimikado Maika (and the drum she was riding around), Index hurried back to the dorm. However, she strayed from the main road on the way and entered a back alley. She walked to a rectangular space surrounded by buildings on all four sides. It was too gloomy to be called a plaza and it had likely been created when a smaller building was demolished and nothing new was built in its place.

The calico cat mewed as she held it in front of her chest.

There was no other sound than that and there was no one else there.

“Bastet.”

However, the girl named Index spoke clearly.

“A goddess from Egyptian mythology. She was the goddess of the Nile’s blessing and of agriculture and she was often drawn with a woman’s body and a cat’s head. Also, her worshippers viewed cats as sacred, worked to please the cats they viewed as her messengers, and used them as agents to communicate between man and god.”

She was not speaking to herself.

Her words were directed at someone.

Index stored the originals of 103,000 grimoires in her head and hostility filled her gaze.

And that gaze was turned toward the calico cat in her arms.

“How about you come on out? I’d like to have my Sphinx back.”

Her only response was a slight pain in the back of her hand.

The usually obedient cat had scratched her. She loosened her grip more due to the suddenness than the pain and the kitten named Sphinx slipped from her grasp.

It skillfully landed on the filthy ground, backed away, and faced her.

And words slipped from its small mouth.

“Tch. So I failed to steal the cat.”

No.

A gust of wind blew past the cat and it revealed the physical body of a girl not all that different from Index.

She was a brown-skinned magician with long black hair.

“I had hoped to peer inside your head using a cat as they are the ‘beasts that carry words of the gods’, but that failed too. Then again, it’s really your fault for giving your cat a name like that. Once I hear that, how am I supposed to resist using it?”

She wore a pink camisole dress that reached almost down to her ankles, but the material was so thin that her entire body was almost visible through it. That alone was enough to leave an impression, but it was just the beginning for her. Her most noticeable characteristic was the black hooded cloak that hid her entire silhouette.

Her odd vertical slits for pupils and the cat ear design on the top of her hood were likely related to the goddess she served.

She was an Egyptian magician.

The white girl observed the cat priestess and spoke to that mystical black cat.

“What do you want?”

“Oh, c’mon. I already said I wanted to peer into your head which we both know holds 103,000 grimoires. Surely that’s enough to figure it out.”

“That isn’t what I meant. Why do you want to put together a new grimoire in my head?”

“…”

It had taken her only one second to see through it.

Just as the Priestess of Bastet froze for a moment, Index continued as if slipping another thin blade in between the gears.

“When I was speaking with Short Hair, a big truck blew dust into the air. There was a description related to the Nile incorporated into it. Of course, the completed text only lasted a twentieth of a second, so a normal person may not have been able to read it.”

That was why Index had offered them the money. She had realized she might have gotten them involved in some kind of magical issue.

“When I was watching the taiyaki stand with Hyouka, the waitress dropped and broke a small bottle. The original bottle had to have had some hieroglyphs written in faint ink. There were 152 shards in all, including the ones smaller than a millimeter. You could read what was written on the original bottle by arranging all those shards in your head.”

That was why Index had said the city was like a labyrinth. Seeing the hieroglyphics of Egyptian mythology in an environment of hard surfaces made of asphalt and concrete had somehow reminded her of the pyramids and megaliths.

“When I was talking with Maika, I saw a popped balloon. The balloon also had something written on it. By imagining the remaining pieces expanded and combined into the inflated balloon, I could picture the true string of writing.”

That was why she had mentioned a summoner. The hieroglyphs she was seeing here and there were the forms of the ancient gods and that had brought a related term to mind.

Index stared directly at the cat priestess and she spoke.

“You used the story of cats stealing information and placed fragments of text around so I wouldn’t notice them. That way you could put together a book in my head and then steal it from my head without me ever noticing. I’m pretty sure that was your intent, but why? To break down the information and alter it into countless hints like that, you had to have already possessed the original book. I don’t understand why you would have me reconstruct it.”

“I see. So this is the grimoire library.”

The girl who served the cat goddess Bastet toyed with the triangular ear design of her hood.

“By the way, I assume you already know what grimoire I was trying to build in your head.”

“I don’t know a method to have someone put together a jigsaw puzzle and yet not see the completed picture,” replied Index in a lovely yet sharp voice. “The Book of the Dead. The papyrus grimoire buried in the pyramids with the mummies in order to one day return the pharaoh’s soul to this world.”

“That’s enough.”

The girl gave a fierce smile.

That smile was as intimidating as the large cat said to be the king of beasts.

“I only needed to know it had been properly put together in your head. Using the cat failed, but I have other methods. I can even break open your skull and pull it out that way.”

“…”

“And you called me Bastet, but I’ll have to dock a few points for that one. It’s not entirely wrong, but it’s not entirely right either. I guess even a grimoire library makes mistakes.”

As she spoke, the cat priestess brought her index finger to her mouth and lightly bit the tip.

“I am a priestess of Sekhmet. I serve that goddess of shed blood and slaughter who is symbolized by the lioness and is sometimes seen as identical to Bastet, goddess of fertility and production.”

A moment later, a bestial claw that resembled a knife burst from her bloody fingertip.

Sekhmet was a goddess often depicted with a woman’s body and a lioness’s head. She was the wife of Ptah, the highest god in Egyptian mythology, and she was an extremely powerful goddess of war. She would use the strength of a lion to thoroughly rip apart any unbelievers or traitors to the faith and she would achieve pure ecstasy while bathing in the pouring rain of blood produced by her slaughter.

Just like Durga from Indian mythology or Frigg from Norse mythology, she symbolized the cruelty and violence of women that was usually kept hidden.

She was a goddess created from a concentrated extraction of all the most frightening aspects of a woman.

And a priestess that served that goddess needed that same power.

Meaning…

“Ha ha.”

She awakened that mindset by entering a trance.

And she gained the great strength of a lion even if it meant temporarily transforming her physical body.

By bringing the two together, she raised herself to a being that wielded the scorching claws and fangs of a beast with the wise mind of a goddess.

She used the bestial claws extending from her fingers to tear at her own chest inside the black cloak. This was a ritual of Sekhmet, goddess of shed blood and slaughter. While she ripped apart traitors of the faith and bathed in their blood, she also grew deeply intoxicated in the overflowing blood of her own flesh. Her priestess could more strongly expose her bestial side by harming herself. This was not the lion seen in a zoological encyclopedia. This was the legendary beast created solely in the human imagination and she was drawing out its power for her own use.

She would fulfill her role as servant of Sekhmet.

She would gain power by slaughtering any traitors of the faith and bathing in their blood.

She did not need to develop any large-scale mysticism or secret art. She simply had to pursue the ability to kill.

And that pursuit led to the power of a beast: claws and fangs.

(Let’s get this over with.)

Merely gathering a bit of strength in her fingers sent a great creaking sound throughout her body. The sound was loud enough to have ruptured the eardrums of a normal person.

(It doesn’t matter what happens to her as long as the head remains. If I open the skull and take out the information within fifteen minutes, I can obtain the Book of the Dead without damaging it!!)

The distance of a few meters no longer mattered.

Even if that entire distance had been filled with thick concrete, she could have torn through the center of the nun’s slender body with a swing of her arm.

So…

And yet…

“Oh, so that’s it.”

In the twentieth of a second it took her to swing her arm horizontally, the Priestess of Sekhmet thought she heard those words.

It was not a voice. A voice would not have propagated through the air quickly enough to reach her.

This was a technique used by a certain type of magician when they needed extremely high speed incantations. Index used that to transmit her thoughts to the Priestess of Sekhmet through the movements of her lips rather than her voice.

The girl casually butted into the realm of high speed that supposedly only belonged to the priestess.

The girl known as Index now existed in that realm.

(No.)

The Priestess of Sekhmet finally felt a chill run down her spine.

But it was too late. She had already started swinging her arm horizontally. She could not cancel that action now.

(She exists in a realm of speed even higher than mine!?)

And to add to that.

(She’s noticed my claws, but she isn’t trying to avoid them. She isn’t even blinking!? What does she have hidden up her sleeve in her realm of even greater speed!?)

But no matter how excellent Index’s perfect memory was, that was all she had. Even if she could analyze the 30 fps of animation or the 60 fps of a fighting game, she could not move around in a thirtieth of a second and slip past an attack from the king of beasts.

All she could manage was to determine what was happening and use the lip movements of ultra high speed incantation to transmit a short text to the Priestess of Sekhmet who had the speed of a beast.

However, that was enough.

She was the grimoire library that had gathered 103,000 grimoires.

She was a specialist in instantly determining a countermeasure for all types of magic and attacks.

(I just have to surprise her.)

The frighteningly intelligent part of her reached that answer.

All she could do was move her lips.

It was not that she did not even blink. She could not even blink.

However, it was enough to confuse the Priestess of Sekhmet.

Bit by bit, those little things would accumulate and bring fatal confusion to her mind.

(A trick creates an instantaneous gap in your opponent’s thoughts, but that instant will be a fatal delay for you. After all, your body will continue to move in that time.)

Ten seconds to a bicycle and ten seconds to a car were entirely different.

The same could be said of a car on the highway and a racecar on the circuit.

The difference was even more pronounced between a racecar at full speed and a supersonic fighter at full speed.

A moment of distraction or an instantaneous gap in one’s thoughts would have serious consequences if enough speed was involved.

“Gah.”

The girl cried out from close by.

As Index was moving at normal speed, the cry was distorted as if by the Doppler effect.

The gap in her thoughts had caused the Priestess of Sekhmet to lose control of her own body, misstep, lose her balance, and rotate as if she had slipped.

The claws that should have reached Index instead cut through the air a few millimeters away from her nose.

And that was as far as she got.

The Priestess of Sekhmet’s body flew through the air while rotating. Not only did she trip on her own, she flipped through the air at least twice and began to fall. Her back slammed into the hard ground.

This was not an aikido method using leverage or shifting body weight. It looked more like a strange qigong technique or a finishing blow in spirit sumo, a type of ritual dance in which a jujitsu specialist would enter the arena alone and play the role of being thrown by a god.

An explosive sound burst out after a short delay.

The Priestess of Sekhmet had difficulty breathing, but Index looked down on that lion who had a black cloak over her head.

“You are not the lion goddess Sekhmet.”

“Kh.”

Psychologically these words could easily become a fatal blow.

“If you were, you couldn’t have tried to use a cat to steal information in your original plan. That is why you must be Bastet, goddess of fertility and production. You are a priestess of the cat goddess, not the lion goddess.”

“…Ah…kah…!!”

The girl referred to as Bastet tried to argue, but she still could not breathe.

And so the nun continued giving her answers.

“And Sekhmet was actually inside my head. You constructed the Book of the Dead there. That is the grimoire buried with the mummies of the pharaohs, but unlike the Book of the Law or the Golden Bough, it is not a single book with a decided format. In order to allow the pharaoh to return from the underworld, each individual copy must be custom made in accordance with the specific pharaoh’s deeds and sins. For that reason, a new grimoire must be made each time a new person dies.”

“Si…lence!!”

“What were you hoping to do with this Book of the Dead?” asked Index. “Why did you want to read the deeds and sins of the dead person named Sekhmet?”

That person had refused to take on apprentices, so the girl had been forced to learn her techniques through observation instead of being taught them. Even so, the girl could now say that she had been built up by her.

There was something the girl had only realized once she had lost that person she had looked up to: she knew nothing about that person. She wanted to tell the world about the person, but she had no way of determining if any of it was accurate.

That was why she had wanted to know.

That was why she had wanted to read it all.

She had wanted to learn what that person had done in her life and she had wanted to know what rewards and punishments that person had earned. That magician had never revealed her past to anyone, so the girl had wanted to read the Book of the Dead that magician had written in her life.

She was not thinking of anything as grand as calling back that person’s soul or eternally preserving her corpse. She simply wanted to tell the world about that person and explain what kind of person she had been. Surely that much could be allowed.

That person had gone to her grave without a single complaint and had remained silent about all that, so she may not have wanted anyone to speak of her. She may not have desired any of this.

However, the girl wanted to understand her no matter what.

After all, the records said that person was terribly cruel and merciless and that she was nothing but a goddess of shed blood and slaughter. The people believed that was the proper view of her, so the girl had wanted to express some simple facts like that the person had had a weakness for sweet foods or that she had always charged straight into the battlefield when she had heard a crying child, even if she had nothing to gain in that battle.

So…

For that reason…

The girl troubled by all this had become afraid that she herself had not truly known the person she had looked up to.

Just like the other ignorant people, what did she actually know of that person?

The Priestess of Bastet practically gasped out the words while lying on the ground.

She glared at Index and at the human intellect that had defeated the beast.

“I had her Book of the Dead…but it was incomplete. The diagrams…were missing…due to tomb robbers. I needed…those diagrams…so…”

“Oh, so that’s it,” muttered Index.

Grimoires could be transmitted from one person to another. There would remain only the one original, but a copy could be newly made.

When that happened, the illustrations and diagrams caused the most trouble.

In consecutive editions, even the grimoires covering the ceremonies for the Golden magic cabal had alterations to the magic circles, rose symbol, and other descriptions that needed to be seen to understand. (Most of the changes were made to make them look fancier and more impressive.) The text alone was not enough for a grimoire. Without both the correct text and the correct diagrams, the true wisdom could not be reached. Human ignorance and vanity would hide the key somewhere.

The Priestess of Bastet had madly sought that.

She had held the incomplete text in her heart and searched for the lost illustrations and diagrams.

The scattered jigsaw puzzle had not had enough pieces, so she had used Index’s head to fill in the gaps.

Even if the grimoire was incomplete, her 103,000 grimoires could be used to fill in the missing pieces after observing those gaps from countless angles.

If it was then stolen from her head, the Priestess of Bastet would have a complete Book of the Dead with both the text and diagrams.

She would have the full records of a certain individual’s life, deeds, rewards, and punishments.

She would have the true picture of that person with no falsehoods mixed in.

“I will reach her.”

She could not gather strength in her body.

She knew that better than anyone.

But despite lying on the ground, the Priestess of Bastet extended a shaking hand straight upwards as if to grasp the sun. Beyond that hand was the girl who had memorized and managed a great number of grimoires.

“Bastet will reach Sekhmet… I have to. I will take back…the diagrams…and truly understand her. And to do that…I must…I must…!!”

“…”

After hearing that, the white nun named Index took in a quiet breath.

And…

“ ‘This is for the best, Leep. Instead of being trapped by me, you should become a freer magician. That is the true correct answer.’ ”

Those few dozen words were enough for the Priestess of Bastet to completely lose sight of reality.

“What?”

The tone of voice was that of a lovely girl.

However, the tempo, accent, breaths, and everything else were all those of the person she knew very well.

That person had descended to this place.

“ ‘To be honest, I was confused by how much you looked up to me. I was not that kind of person, but at the same time, I was happy. That was why I refused to take you on as an apprentice and yet continued to partially respond to what you wanted. I should have outright refused you, but I was afraid of losing you. I’m sorry.’ ”

(No.)

The black cat thought in her confusion.

(I don’t know anyone with such a kind look in her eyes.)

As she thought long and hard, the Priestess of Bastet finally realized what was happening.

She herself had obtained the Book of the Dead and read it. It had described all the good and bad deeds of that person, but it had never mentioned the kind of person she had been.

That information was not in the text.

These were the lion’s unwritten words that one could say were between the lines.

The ultimate version had been created in Index’s head by combining the text and the diagrams. By recording the deeds and sins of a certain individual, the custom-made grimoire had been fine-tuned to save the soul of that individual. It was with that grimoire that Index knew this.

This was not a conversation.

It may have looked like it, but it was technically not.

It was like reading a diary entry someone had written long, long ago. The important feelings that someone had long hidden in her heart yet wanted to express someday were being spoken to a dense person who understood nothing.

It was like explaining the true meaning of a book to someone who had read the blurb and shut the book there.

“ ‘I was truly happy when you created a path to Bastet instead of Sekhmet. So become someone who will cover people in a shower of blessings rather than someone like me who covers people in a shower of blood. While you were my greatest trouble, you were also my greatest hope. Do you understand, Leep? Even as you looked up to me, you were a magician who had moved far ahead of me.’ ”

That became the finishing blow.

It was unavoidable.

The physical damage was tormenting her mind to the point that her false conviction and her great desire were the only things keeping her conscious, but the final core of her being broke.

When she heard those words, a barely-noticeable smile appeared on her lips and she was unable to stop the tears from flowing.

And thus the black cat that had looked up to the lion fully let go of her consciousness.